| Bug #25721 | Federated: hang with simultaneous ALTER SERVER and CREATE SERVER | ||
|---|---|---|---|
| Submitted: | 19 Jan 2007 17:28 | Modified: | 30 Mar 2007 19:50 |
| Reporter: | Peter Gulutzan | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: Federated storage engine | Severity: | S3 (Non-critical) |
| Version: | 5.1.15-beta-debug | OS: | Linux (SUSE 10.0 / 64-bit) |
| Assigned to: | Antony Curtis | CPU Architecture: | Any |
[19 Jan 2007 17:48]
MySQL Verification Team
Thank you for the bug report. Verified as described.
[26 Jan 2007 2:03]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/18821 ChangeSet@1.2410, 2007-01-25 18:02:42-08:00, acurtis@xiphis.org +4 -0 Bug#25721 "Concurrent ALTER/CREATE SERVER can deadlock" Deadlock caused by inconsistant order of locking mutexes. Test provided.
[8 Feb 2007 0:45]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/19528 ChangeSet@1.2429, 2007-02-07 16:45:31-08:00, antony@ppcg5.local +4 -0 Bug#25721 "Concurrent ALTER/CREATE SERVER can lead to deadlock" Deadlock caused by inconsistant use of mutexes in sql_server.cc Code has been simplified and opportunity for deadlock removed. Test included.
[24 Mar 2007 1:31]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/22853 ChangeSet@1.2498, 2007-03-23 17:31:27-07:00, acurtis@xiphis.org +5 -0 Bug#25721 "Concurrent ALTER/CREATE SERVER can lead to deadlock" Deadlock caused by inconsistant use of mutexes in sql_server.cc One mutex has been removed to resolve deadlock. Many functions were made private which should not be exported. Unused variables and function removed.
[24 Mar 2007 1:39]
Antony Curtis
pushed to 5.1-engines repository
[30 Mar 2007 17:28]
Bugs System
Pushed into 5.1.18-beta
[30 Mar 2007 19:50]
Paul DuBois
Noted in 5.1.18 changelog.
[4 Apr 2007 21:36]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/23839 ChangeSet@1.2542, 2007-04-04 21:35:58+00:00, acurtis@xiphis.org +2 -0 fix test for bug#25721 did not run properly on a fast Windows machine
[8 Apr 2007 19:01]
Bugs System
Pushed into 5.1.18-beta
Description: I create a procedure which repeatedly says CREATE SERVER and ALTER SERVER. I run the procedure on two connections. After a while, both connections hang. How to repeat: This is a "federated" bug, but there are no federated tables. The hang can be repeated with one machine. Start mysqld. Start two instances of mysql client, T1 and T2. On T1, say: delimiter // drop server s// drop table t100// drop procedure p1// create procedure p1 () begin DECLARE v INT DEFAULT 0; DECLARE v2 INT; DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SELECT 'error'; WHILE v < 1000000 do SELECT v; SELECT 'CREATE SERVER'; CREATE SERVER s FOREIGN DATA WRAPPER mysql OPTIONS (USER 'Remote', HOST '192.168.1.106', DATABASE 'test'); SELECT 'ALTER SERVER'; ALTER SERVER s OPTIONS (USER 'Remote'); SET v = v + 1; END WHILE; END// CALL p1()// On T2, say: CALL p1(); Eventually -- usually within 10,000 iterations on my machine -- both T1 and T2 will hang. If I start a third mysql connection and say SHOW PROCESSLIST, I get the impression that the server is trying to handle an ALTER SERVER and a CREATE SERVER simultaneously.